Improved burglar-alarm



UNITED STATES PATENT OEFIcE.

EDMI'IND HOOLE, OF NEW YORK, N. Y.

IMPROVED BURGLAR-ALARM.

Specification forming part of Letters Patent No. 54,353, dated Mayl, 1866.

To all lwhom it may concern f Be it known that I, EDMUND HooLE, of the city, county, and State of New York, have invented certain new and useful Improvements in Burglar-Alarms; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, making apart of this specilication, in which- Figure 1 is a side View. Fig. 2 is a central vertical section. Fig. 3 is a horizontal section taken in the line a0 @c ot' Fig. 2. Fig.4is a detached plan and av transverse section oi a portion of the invention.

Similar letters ot' reference indicate corresponding parts in all the drawings.

This invention consists in two dovetail tapering slots formed opposite each other in the frame or base-plate of the alarm, and used in combination with a tapering dovetailed plate. iirmlysecured to the door or door-sill, to which the alarm is attached in such a way that the said alarm may be readily applied to either right or left hand doors.

Io enable others to understand the construction and operation ot my invention, I will proceed to describe it with reference to the drawings.

As represented in the drawings, the mechanism for sounding the alarm is substantially the same as that described in Letters Patent granted to A. W. Decrow, and bearing date December 12, 1865, a being the arbor which aetuates the apparatus for striking the bell, and which is turned or rotated by the operating-spring c, coiled around one of its ends, and d being the tripping-bar, the movements ot' which release theliammer c and allow it to sound the alarm.

All the moving parts ot' the appara-tus are supported onta frame or base-plate, A,around the periphery ot' which is a raised rim or flange, b.

B is the bell, which may be of such a form as to cover or inclose the workingparts of the apparatus, as shown in Figs. 1 and 2, and which is iirmly secured to the extremity of the arbor a, the said extremity being made square or polygonal in form, and fitted into a hole of v corresponding shape in the center of the bell B, which is permanently secured thereon by means of a nut, n, screwed upon the end of the arbor above the bell. The said arbor can thus be turned or rotated to coil or wind up the operating-spring c by simply turning or rotating the bell, the arbor being prevented from turning backward when the spring is coiled by means of a pawl, j, and ratchet h, applied to it in the ordinary way.

Formed in the base-plateA aretwo dovetail tapering slots, D, which extend inward from opposite points of the periphery of the said base-plate to the. center thereof, the said slots tapering as they approach the center of' the base-plate and being made of dovetail form, or, in other words, narrower at the outer side otl the base-plate than at the inner side thereof', as clearly shown in Figs. 1 and 2. These opposite slots D D are both of the same shape and size. At E, Fig. 4, is shown a tapering dovetail plate so shaped and of such size as to tit closely but easily into either of the dovetail slots D. This plate is secured either to the door-sill or to the door itself, as required, by means ot' screws, with its broadest side outward and its narrowest end uppermost, so that the alarm can be suspended on the said plate by placing the base A upon it, with the plate E fitting closely in one of the slot-s D, the dovetail and tapering form ot' the slot and plate causing them to hold firmly together, the alarm being placed in the same position with reference to the door and the sill thereof as set forth in the hereinbefore-nientioned patent, dated December 12, 1865.

Inasmuch as the slots D are situated opposite each other, the alarm maybe placed either side up upon the plate E, in order to bring either end of the'tripping-bar d across and opposite the edge ot' the door or sill, as required, thus adapting the apparatus to either right or lei't hand doors.

What I claim as new, and desire to secure by Letters Patent, is

The dovetail tapering slots D, situated opA posite each other in the frame or base-plateA of a burglar-alarm, in combination with the tapering dovetail plate E, substantially as and for the purpose speciiied.

EDMUND HOOLE. Witnesses: v A. LE CLERC, J. W. CooMBs. 

